Folding box sheet blank



Oct. 8, 1963 A.R.RAus1NG 3,106,330

FOLDING BOX SHEET BLANK Filed oct. 25. 1961 Fg.1 l

l 1o 1I 1o 3 12 12 g 11 Fig.2

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BY QAW $4, ATTORNEYS 3,106,330 FLDING BOX SHEET BLANK Anders RubenRansing, Simontorps Sateri,

Blentarp, Sweden Filed Oct. 25, 1961, Ser. No. 147,503 Claims priority,application Sweden (let. 25, 1%@ 3 Claims. (131. 229-14) along lateralcrease lines or the like-a corresponding number of end closure panels,which in turn are hinged to said side wall panels along crease lines orthe like dened by equipo-sitioned side wall panel ends, and border uponl each other substantially `along imaginary extensions of said lateralcrease limes, the lblank being adapted, through holding about saidlateral crease `lines and the extensions thereof, said plastic layerfacing inwards, and through joining laterally to each other the twooutermost side wall and end closure panels, respectively, possibly bymeans of corresponding seaming flaps 'likewise delined by said lateraland said end crease lines, to set up `into a sleeve open at the two endsthereof and having said endcrease lines contained in one and the sameplane, and, subsequently, to close into a4 container through foldingsaid end closure panels outwards into said plane, thereafr sealing, in adat shape and to Ka re-entrant rim zone of said plastic layer, lasealing sheet extending beyond the sleeve end opening rim dened by saidend crease lines, and, tinally, folding said end closure tlaps inwardsover said sleeve end opening While securing them in their infoldedposition.

At least in an indirect way, folding box sheet blanks of the kind inquestion yare previously known eig. through US. specification No.2,886,231 relating to iilled and sealed folding box packages pnoducedfrom a sheet blank the end closure panels of which as -Well as theassoci-ated lateral end closure fiaps are separated from each otherthrough cuts in the extensions of the lateral crease lines. The cuts inquestion pass through the carrier sheet material Aas well as through theplastic layer of the laminate sheet material and extend from theadjacent outer edge of the blank toV a point at a ydistance from the endcrease lines tnansverse to said side crease lines, defining between theinne-r end of the respective cuts and said end crease lines an intactgusset tof said laminatesheet material. When setting up the .blank intoa box sleeve and closing the ends thereof the Ibody portion tod saidgusset will liber, While its plastic layer portion will stretch therebyto dorm, at each corner of said package end opening, 'a plastic coveredfibre tuft to the plastic lilm of which the sealing sheet may be sealed.

When tibering into .a tuft the gusset body portion still laminated tosaid plastic layer there can hardy be avoided that the libres, due tostress concentration or penetration will cause holes or pores in theplastic film simultaneously stretched. As in many cases these holes willbe concentrated to the proximate vicinity yof the box corner and Cil3,165,33@ Fatented Oct. 8, 1963 ice even to said end crease lines, theapplication of the'sealing sheet over the end opening and its sealing tothe plastic layer surrounding said end `opening are likely, in maycases, not to yield a liquid-tightly closed box end.

The :folding box sheet blank according to the present invention willavoid such drawback. Thus, the folding box blank in question has as itsmain feature that said end closure panels and possible associatedlateral seam flaps are, with respect to said body layer, completelyseparated and severed from each other and having lateral edges of such ashape determined by the severance that overturning outwards the endclosure panels of the sleeve as set up will, without lupt-uring, stretchthe intact plastic layer portion between adjacent end closure panels todorm an outwarldy projecting gusset.

ln the dollowing the invention will be described in greater detailreference being made to the accompanying Y drawing, wherein FIG. l is aplane view of a folding box sheet blank according to lthe invention,

FIG. 2 is a cross-sectional view of a portion of the sheet material fromwhich the blank is produced,

FlG'. 3 is a perspective view of the box set up from the sheet blank andhaving its end closure panels overturned outwards, and

FlG. 4 illustrates in perspective View land on -a larger scale onecorner of the folding box .as setup and with its end closure panels`overturned outwards.

The folding box sheet blank according to the invention comprises aplurality of side wall panels 1, 2, 2 and 2 as well as .a correspondingplurality of end closure panels 3, 4, d and 4l". The side wall panelsconnect consecutively to each other along lateral crease lines 5, theend closure panels being hinged to equipositioned side wall panel endsalong end crease lines 6 transverse to the lateral creases lines and, inaddition, bordering upon each other substantially along imaginaryextensions of the lateral crease lines 5. A

The folding box blank is assumed to be produced from a laminate materialconstituted of a carrier sheet material 7 and a stretchable plasticlayer 3` laminated to one face ot said carrier sheet material in asubstantially who-lecovening relationship thereto :and comprising e.g.polyethylene, as shown in FIG. 2.

When setting up into box shape the blank is intended to fold along thelateral crease lines 5 and their extensions with the plastic layer Sfacing inwardly, and thereafter 'to have its two outer side vwall panelsand end closure panels, respectively, joined in a lateral seam. In thepresent case illustnated such later-al seeming implies that the partialpanels 2 and 2" and the partial panel portions Il and 4, respectively,in :overlapping relationship and along their free side edges are joinedto 4form a side wall panel 2, and an end closure panel 4, respectively.However, the lateral seam might as Well be positioned in the vicinity ofa folding box corner `instead of substantially along the axis of saidside wall panel 2, and said end closure panel 4, respectively. However,this will require that no side Wall panel 2 be divided into two partialpanels 2 and 2; that no end closure panel 4 be annesso in the same wayas the side wall panels and the end closure panels.

With respect to the plastic layer S the end closure panels `and possiblelateral seam flaps are integral along at least that portion of theimaginary extensions of the lateral crease lines closest to the endcrease lines 6. With respect to the carrier layer 7, however, they arecompletely separated or severed from each other ail the Way from thecorresponding outer edge of the blank to the end crease lines. Inaddition, their lateral edges determined by the severance yare of such ashape that overturning outwards the end closure panels 3 and 4 of thelaterally seam-ed sleeve set up from the blank will, without rupturing,stretch the intact plastic layer portion between adjacent end closurepanels to yform an outwardly projecting gusset 9, see FIGS. 3 and 4.

In the case illustrated, the end closure panels up to a distance L (FIG.4) from the end crease lines 6 are completely separated from each otherby a cut 16 through both the carrier layer 7 and the plastic layer 8 andin the extensions of the lateral crease lines 6. At the inner end of thecut 10 there is provided in each end closure panel a triangular notch 11affecting only the carrier layer 7 of the end closure panel margin. Thatis to say, as regards the carrier layer 7, adjacent end closure panelsare separated along both the cut lines l@ and notches 11, but as regardsthe plastic layer 8, the adjacent end panels are separated only alonglines 10. Said notch 11 is deiined, on one hand, by a line 12substantially parallel to the respective end crease line and extendingthrough tde innermost end of the cut 10, and, on the other hand, by aline 13 extending from the intersection of the respective end creaselines and lateral crease lines at an inclination angle cc with respectto the end crease line, Where should fulfil the following requirement,Viz.

where S=the elongation or stretch coeicient of the plastic layer.

Plastic layers of the kind in question have an extensibility of about 3to 5 times its original dimension. In th present case, to utilize su'chextensibility, however, the intact plastic layer in question betweenadjacent end closure panels should in the direction of stretching have adefinite original dimension at points outside the intersection betweenthe end crease lines and the lateral side crease lines. It is easilyunderstood that the transverse original dimension of the plastic layershould grow as a linear function of the distance from said intersection.

When setting up the blank into sleeve shape the end crease lines 6 willbe positioned in one and the same plane, the end closure panels 3 and 4being subsequently overturned outwards substantially to lie in saidplane, as indicated above. For sealing closed the box end in questionthere is applied over the opening defined by the end crease lines a flatsealing sheet 14 (FIG. 3) extending beyond said opening in all pointstherealong. Suitably, such sealing sheet constitutes of or is coatedwith a plastic layer heat-scalable to the plastic layer The sealingsheet 14 is sealed to the plastic layer S in a re-entrant seal 15extending along the end opening. The seal 15 also includes at least aportion of each gusset 9.

In a conventional manner the end iiaps 3 and d are infolded to lie overthe end opening and are secured to each other thereby to yield acontainer sealed closed at the corresponding end thereof.

The gussets 9 oier a relatively large sealing surface, and therefore aliquid-tight container (or package, in case of a folding box closed atboth ends thereof in the same way) results. In FIG. 4 this isillustrated by dimension h which may be expressed by The above specificembodiment may, of course, undergo modifications in several respectswithin the scope of the present invention. For example, only one of twoopposite carrier layer edges of adjacent end closure panels 3 and 4 needbe provided with a substantially triangular notch, the inclination angleoc in that case, however, possibly requiring a corresponding change and,of course, calling for other limits. Furthermore, it should beunderstood that the sheet blank according to the invention along twoopposite ends may be provided with end closure panels corresponding tothe end closure panels 3 and 4 disclosed above and shown in the drawing,in which case the blank may be set up and sealed closed into acompletely sealed container.

Though, for sake of simplicity there has been :disclosed herein afolding box blank to be set up and sealed into parallelepipedon shapethe invention, of course, is applicable to blanks for folding boxes of across-section successively growing from one box end to the other. Norneed the side wall panel number correspond to four side wall box but mayvary for obtaining folding boxes having a side wall panel number lessthan or exceeding four.

In principle, the blank according to the invention may be produced bytwo ydifferent methods. According to one method the carrier sheetmaterial 7, before laminating or coating the plastic layer 8 thereto,will be provided with through-apertures corresponding to the notches 11,Subsequently, the plastic layer v8 is applied. In a iinal operation, thelaminate material is then provided with the lateral crease lines S, theend crease lines 6, and the cuts 10. In case the coating or laminatingof the plastic layer may be limited in such a way as to leave uncoatedor exposed those sections of the end closure panels 3 and 4 outside ofor beyond the notch cut edge portions substantially perpendicular to theextensions of the lateral crease lines 5, of course, the cuts 10 may beprovided more or less in direct connection with the provision of thenotches 11.

According to the other method above indicated the notches 11 of thecarrier layer 7 may be provided on the iinished laminate materialproper. For that purpose, there may be utilized a milling or cuttingoperation making possible the substantially complete removal of thecarrier sheet material portion corresponding to the notches 11, thecorresponding portion of the plastic layer 3 being left substantiallyintact. The crease lines 5 and 6 as well as the cuts 1t) may be providedin connection with the provision of the notches 11 but might as well beprovided separately both with respect to each other and in relation tothe removal of the carrier sheet material of the notch areas 11.

I claim:

1. In a carton blank, the combination comprising a laminate materialconstituted by a carrier sheet of paperboard and a heat scalablestretchable plastic layer bonded to said paper-board sheet andsubstantially coextensive in area therewith, a first set of spacedlongitudinally extending crease lines on said laminate material denningtherebetween a plurality of side wall panels, end closure iaps providedon at least one end of said side wall panels and hingedly connectedthereto along transversely extending co-linear crease lines, thepaper-board sheet portions of adjacent end closure flaps being separatedfrom each other by a cut extending from the outer ends of said endclosure iiaps to said co-linear transverse crease lines and an innerportion of said cut diverging outwardly from the point of intersectionof the appertaining longitudinal and transverse crease lines toestablish a notch portion, and the plastic layer portions of saidadjacent end closure flaps also being separated from each other alongsaid cut from the outer ends of said end closure aps inwardly but onlyso far as said notch portion, whereby upon a turning outward of said endclosure iiaps from thc corresponding side wall panels during the processof erecting 5 i the carton, that portion of said plastic layer overlyingsaid notch portion will stretch without rupturin-g to establish anoutwardly projecting gusset between adjacent outwardly turned endelosure aps.

` 2. A carton blank as defined in claim l wherein said `15Y notchportion has a substantially triangular configuration with the base edgethereof parallel to said transverse crease lines.

3. A |carton blank as defined in claim 1 wherein said notch portion hasa substantially triangular con'kguration 10 and the remaining portion ofsaid out is rectilinear and in alignment with the appertaininglongitudinally extending tcrease line.

References Cited in the file of this patent UNITED STATES PATENTS2,553,803 Zinn May 22, 1951 2,996,235 Turpin Aug. 15, 1961 Y FOREIGNPATENTS France Mar. 26, 1958

1. IN A CARTON BLANK, THE COMBINATION COMPRISING A LAMINATE MATERIALCONSTITUTED BY A CARRIER SHEET OF PAPERBOARD AND A HEAT SEALABLESTRETCHABLE PLASTIC LAYER BONDED TO SAID PAPER-BOARD SHEET ANDSUBSTANTIALLY COEXTENSIVE IN AREA THEREWITH, A FIRST SET OF SPACEDLONGITUDINALLY EXTENDING CREASE LINES ON SAID LAMINATE MATERIAL DEFININGTHEREBETWEEN A PLURALITY OF SIDE WALL PANELS, END CLOSURE FLAPS PROVIDEDON AT LEAST ONE END OF SAID SIDE WALL PANELS AND HINGEDLY CONNECTEDTHERETO ALONG TRANSVERSELY EXTENDING CO-LINEAR CREASE LINES, THEPAPER-BOARD SHEET PORTIONS OF ADJACENT END CLOSURE FLAPS BEING SEPARATEDFROM EACH